Vital sign display and its method

ABSTRACT

A vital sign display device and method which allows a vital sign to be checked easily is provided. A vital sign item name is displayed at the center of a circle radar ( 50 ). The circle part of the circle radar ( 50 ) is colored in gray, for example, at the beginning of the measurement. An indication point moves clockwise in the circle radar ( 50 ) as the measurement time proceeds. Green is displayed while VPCs (ventricular premature contractions) do not occur, and red is displayed when VPCs occur.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of patent application No.2002-246627, filed in Japan on Aug. 27, 2002, and the subject matter ofwhich is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device and a method for displaying avital sign and more particularly for facilitating the check ofbiological signal.

2. Description of the Related Art

In the technical field of displaying biological information such asblood pressure or electrocardiogram, some techniques have been developedto allow the biological information to be easily checked. There is atechnique for displaying an event mark at a time position correspondingto electrocardiographic data during an attack on a trend graph of anelectrocardiographic parameter such as heart rate or ST level (seePatent Document 1, for example). Patent Document 1: JP-A-Hei 4-352939(FIG. 8).

According to the technique, it is possible to determine when attacksoccurred, for example, with the event marks. That is, according to theexisting technique, it is possible to obtain information about whenabnormal values of biological information appeared.

In a medical site, however, a technique to allow for easy visualacquisition of more comprehensive biological information in addition tothe determination of individual abnormal values may be demanded.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a vital sign display device andmethod thereof that are capable of facilitating check of biologicalinformation. The invention includes the following:

(1) A vital sign display device in accordance with the present inventionfor displaying a vital sign, comprises means for obtaining a biologicalsignal, means for determining whether living body condition representedby the biological signal is abnormal or not, which is based on theobtained biological signal, and means for displaying a vital signobtained from the biological signal, that allows to discriminate whetherthe condition is abnormal or not, which is based on the determinationresults from the determining means, wherein the vital sign is arrangedin time series that allows to provide history of the vital sign.

The user who utilizes the results outputted by the vital sign displayingmeans can easily understand that the living body is in normal conditionor abnormal condition. Since the vital sign is successively displayed intime series so that the user can understand the history of the vitalsign, for example, the user can easily understand information regardingtiming in which the patient's abnormal condition occurred and frequencyof occurrence of the abnormal condition.

(3) A vital sign display device in accordance with the present inventionfor displaying a vital sign, comprises means for displaying a vitalsign, obtained from the biological signal or signal generated from thebiological signal, that allows to discriminate whether living bodycondition represented by the signal is abnormal or not, wherein thevital sign is arranged in time series that allows to provide history ofthe vital sign.

The user who utilizes the results outputted by the vital sign displayingmeans can easily understand that the living body is in normal conditionor abnormal condition. Since the vital sign is successively displayed inmeasurement sequence so that the user can understand the history of thevital sign, for example, the user can easily understand informationregarding timing in which the patient's abnormal condition occurred andfrequency of occurrence of the abnormal condition.

(4) The device in accordance with the present invention is characterizedin that the vital sign is displayed so as to follow a circular shapeaccording to time series of the vital sign.

The device can, to some extent, prevent display area for the vital signfrom extending or spreading according to the passage of measurementtime. Therefore, the user who utilizes the results outputted by thevital sign displaying means can easily make a visual identification fora general trend of the vital sign.

(5) A vital sign display device in accordance with the present inventionfor displaying a vital sign, comprises means for obtaining a biologicalsignal, means for determining whether living body condition representedby the biological signal is abnormal or not, which is based on theobtained biological signal, and means for displaying a vital signobtained from the biological signal, that allows to discriminate whetherthe condition is abnormal or not based on the determination results fromthe determining means, wherein the display is executed by moving adisplay object in the direction to draw a circular shape according totime series of the vital sign.

The user who utilizes the results outputted by the vital sign displayingmeans can easily understand that the living body is in normal conditionor abnormal condition.

(6) The device in accordance with the present invention, ischaracterized in that the device further comprises means for selectingdisplay style, and the display style selecting means selects length ofentire display period corresponding to display area for the vital signby correlating with measurement period of the vital sign.

The length of display time corresponding to display area can be adjustedin accordance with the measurement period of the vital sign.

(7) The device in accordance with the present invention, ischaracterized in that the device comprises means for displaying itemname of vital sign, and the vital sign item name displaying meansdisplays the item name by relating the item name to the displayed vitalsign.

The user who utilizes the results outputted by the vital sign displayingmeans can easily understand that which of the vital sign items isrelated to the condition of vital sign.

(8) The device in accordance with the present invention, ischaracterized in that the display style of vital sign is changed toanother style when the abnormal condition occurs.

The user who utilizes the results outputted by the vital sign displayingmeans can easily make a visual identification for an abnormal conditionof the living body.

(9) The device in accordance with the present invention, ischaracterized in that the vital sign comprises at least an item of VPC(ventricular premature contraction), HR (heart rate), QT interval, orSpO₂ value (oxygen saturation in blood).

The user who utilizes the results outputted by the vital sign displayingmeans can easily make a visual identification for the vital sign of theVPC, HR, QT interval, or SpO₂ value.

(13) A vital sign displayed object in accordance with the presentinvention, representing a vital sign, is characterized in that the vitalsign displayed object represents a vital sign obtained from a biologicalsignal, that allows to discriminate whether living body conditionrepresented by the biological signal is abnormal or not, wherein thevital sign is arranged in time series that allows to provide history ofthe vital sign.

The user who utilizes the results outputted by the vital sign displayingmeans can easily understand that the living body is in normal conditionor abnormal condition. Since the vital sign is successively displayed intime series so that the user can understand the history of the vitalsign, for example, the user can easily understand information regardingtiming in which the patient's abnormal condition occurred and frequencyof occurrence of the abnormal condition.

The followings are definitions of the terms.

“Biological signal” is a concept that includes any biologicalinformation or information about the pathologic conditions. The“biological signal” includes individual values (parameters) thatrepresent biological information and information represented based on aplurality of pieces of biological information.

“Vital sign” is a concept that includes anything which is displayedbased on a biological signal to make it possible to determine whether acondition of a living body represented by the biological signal isabnormal or not. For example, the concept includes changing the shape orcolor of displayed object to make it possible to determine whether acondition of a living body is normal or abnormal in addition to specificcodes, symbols, marks, figures and letters which make it possible todetermine whether a condition of a living body is normal or abnormal.

“Vital sign item name” is a concept that includes names representingmatters relating to biological information. For example, the conceptincludes the names of parameters which represent matters relating tobiological information, the names of pathologic conditions and the namesof diagnosis.

“Normal” is a concept that includes a right (ordinary) state and anon-abnormal state in addition to a case where it can be determined thatthere is no disorder. For example, the concept includes a case where avalue representing biological information is in a range within which thevalue falls when a living body is in good condition or determined as notabnormal by a specific determination method.

“Abnormal” is a concept that includes a non-right (non-ordinary) stateand a non-normal state in addition to a case where biologicalinformation indicates that there is a disorder. For example, the conceptincludes a case where a value representing biological information is outof a range within which the value falls when a living body is in goodcondition or determined as abnormal by a specific determination method.

“To determine whether a living body is in an abnormal condition”includes to determine the presence or absence (or the degree) ofabnormality, to determine the presence or absence (or the degree) ofnormality, or to determine whether the subject matter is normal orabnormal (,or to determine the degree of normality or abnormality of thesubject matter).

“Circular shape” is a concept that includes any shape around which onecan make a circuit. For example, the concept includes a loop shape, ringshape, circle shape, round shape, oval shape, doughnut shape, annularshape, and polygonal shape formed by straight lines, curves or acombination of straight lines and curves.

The features of the present invention can be described broadly as setforth above. The structures and characteristics of the present inventionwill be apparent from the following detailed description of theinvention together with those features, effects, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 1C, and 1D illustrate schematic view of displayed vitalsign circle radar according to an embodiment of the present invention.

FIG. 2 illustrates a function block diagram of a vital sign circle radardevice according to an embodiment.

FIG. 3 illustrates a hardware configuration example for the vital signcircle radar device according to an embodiment.

FIG. 4 illustrates a screen example of vital sign circle radar accordingto an embodiment.

FIG. 5 schematically illustrates stored ECG wave data as a graph formaccording to an embodiment.

FIG. 6 illustrates a program flowchart for process that creates a vitalsign circle radar according to an embodiment.

FIG. 7 illustrates a program flowchart for process that determinesabnormality (i.e., for ventricular premature contraction (VPC))according to an embodiment.

FIG. 8 illustrates a program flowchart for process that determinesabnormality (i.e., for heart rate (HR)) according to an embodiment.

FIG. 9 illustrates a program flowchart for process that determinesabnormality (i.e., for QT interval) according to an embodiment.

FIG. 10 illustrates a program flowchart for process that determinesabnormality (i.e., for SpO₂ value) according to an embodiment.

FIG. 11A, 11B, and 11C illustrate other examples of a vital sign circleradar display.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vital sign circle radar device as an embodiment of the “vital signdisplay device” will be described below. The embodiments illustratesprocess for displaying vital sign circle radar based on the patient ECGdata etc. According to the following embodiments, for example, the userof the device can intuitively and easily obtain information regardingtiming in which the patient's abnormal condition occurred and frequencyof occurrence of the abnormal condition during transferring the patient.

An overview of the embodiments, hardware configurations of devices,embodiments and structures corresponding to the terms in claims, anddetails of embodiments will be described below.

Table of Contents for the Embodiments

1. Outline of Vital Sign Circle Radar to be Displayed

2. Hardware configurations of devices

3. Embodiments

4. Example of Vital Sign Circle Radar to be Displayed

5. Vital Sign Circle Radar Creation Process

6. Effects of Embodiment

7. Other functions of the vital sign circle radar device

8. Other embodiments

1. Outline of Vital Sign Circle Radar to be Displayed

A vital sign circle radar is a displayed image representing a vital signof a patient obtained from an electrocardiogram or the like. A vitalsign circle radar device 100 for performing the display will bedescribed later. This device is suitable for the use in emergencysituations or in ambulances and hospitals. In this embodiment,description will be made taking as an example a case where it is used byan emergency medical technicians in an ambulance carrying a patient.

FIG. 1 is a schematic view of examples of a displayed vital sign circleradar. FIGS. 1A, 1B, 1C and 1D are images of a circle radar 50 intime-series order displayed on a display screen 14 to indicate thepresence or absence of occurrence of “ventricular premature contractions(VPCs)” as one of vital signs. One cycle of the circle radar 50corresponds to a measurement period of 20 minutes.

As indicated by an arrow 40 in FIG. 1A, an indication point movesclockwise in the circle radar 50 as the measurement time increases (adisplaying object is moved in direction to draw a circular shapeaccording to time series of the vital sign). The vital sign item name isdisplayed at the center of the circle radar 50. The circle part (ringpart or doughnut ring part) of the circle radar 50 is colored in gray atthe beginning of the measurement. After the start of the measurement, itis determined whether there is an abnormality in the vital sign at everyheartbeat and the indication point moves clockwise (see the arrow 40 inFIG. 1A). Then, the color of the ring part is changed depending on theresult of the abnormality determination. That is, the circle radar 50 isdisplayed in such a manner that it can be determined whether the vitalsign is normal or abnormal. More specifically, green is displayed whileVPCs do not occur (normal), and red is displayed when VPCs occur(abnormal) (the display style is changed). In the drawing, the periodsof time in which VPCs did not occur are shown in white and the periodsof time in which VPCs occurred are shown in black for the sake ofconvenience. Since normal and abnormal conditions are displayed incolors different from the gray of the circle part, the progress of themeasurement and the current display position can be visually recognizedwith ease. More specifically, FIG. 1A shows that the vital sign (VPC) isnormal at the moment.

FIG. 1B shows an example of the screen on the display screen 14 at thetime when VPCs occur. When a VPC occurs in a period in the measurementtime, the indication point corresponding to the period is shown(painted) in red as shown in FIG. 1B. More specifically, FIG. 1B showsthat the vital sign (VPC) is abnormal at the moment.

FIG. 1C shows an example of the state of the display screen 14 aftersome more measurement time has passed from the moment when the displayscreen 14 was in the state shown in FIG. 1B. As shown in the drawing,the periods in which VPCs occurred are displayed in red in the circleradar 50. The user of the device can know the history of abnormalconditions (history of the vital sign), that is, when or how often VPCs(ventricular premature contractions) occurred, by viewing the redsections. More specifically, FIG. 1C shows that the vital sign (VPC)indicates that VPCs are occurring (abnormal) at the moment and thatseveral abnormal conditions have occurred in the past. The width of thesections displayed in red represents the length of time for which theabnormal condition continued.

FIG. 1D shows an example of the state of the display screen 14 after themeasurement time has exceeded twenty minutes. When the measurement timeexceeds twenty minutes, the indication point in the circle radar 50moves more than one full turn. Thus, abnormality determination isperformed in the same manner as in the first cycle with a gray sectionwith a prescribed width after the indication point (see the referencenumeral 41 in FIG. 1D), and new information is overwritten on (deletes)the old information displayed during the first cycle. More specifically,FIG. 1D shows that the vital sign (VPC) indicates that VPCs are notoccurring at the moment (normal condition), that the measurement timehas exceeded twenty minutes (in the second or more cycle), and thatseveral abnormal conditions occurred in the past twenty minutes.

The shape and color of the vital sign circle radar 50 and the colors forindicating normal and abnormal conditions are illustrative and can bechanged by means known to those skilled in the art.

The arrow 40 in FIG. 1 is shown to explain the movement of theindication point and thus is not displayed on the display screen 14 inreality. However, the arrow 40 (or a mark similar to the arrow 40) maybe displayed on the display screen 14 to indicate the moving directionor the display position of the indication point clearly.

2. Hardware Configurations of Devices

FIG. 2 illustrates a function block diagram of a vital sign circle radardevice 100. The vital sign circle radar device 100 includes biologicalsignal obtaining means 2, determining means 3, vital sign displayingmeans 4, display style selecting means 6, and vital sign item namedisplaying means 8.

The biological signal obtaining means 2 obtains biological signal. Thedetermining means 3 determines whether the biological signal representsa normal condition or an abnormal condition. The vital sign displayingmeans 4 displays the vital sign that displays the determination resultsas a vital sign circle radar. The display style selecting means 6selects display style of the vital sign circle radar. The vital signitem name displaying means 8 displays item name of the vital sign byrelating the item name to the vital sign circle radar.

FIG. 3 illustrates a hardware configuration example of the vital signcircle radar device 100 shown in FIG. 2 by use of a central processingunit (CPU). The vital sign circle radar device 100 includes CPU 10,amplifier 11, analog-digital converter 12, mouse/keyboard 13, display 14(display device), speaker 15, communication interface 16, memory 17,Flash-ROM 18 (which corresponds to a rewritable read-only memory devicefrom which recorded data can be electrically erased (e.g. theflash-memory), and will be described as “F-ROM 18”), display controller19, and ECG electrodes 20 (biological signal detector).

The ECG electrodes 20 are used for measuring a patient's heart'selectric current. The amplifier 11 amplifies the heart's electricalcurrent obtained through ECG electrodes 20. The CPU 10 controlsoperations of the vital sign circle radar device 100, executes a processthat converts data obtained from the heart's electric current to ECGdata for displaying an ECG, and executes a process that generates avital sign circle radar. The F-ROM 18 stores a computer program forcontrolling the vital sign circle radar device 100. The memory 17 actsas a storage area for data processing performed by the CPU 10. Operationinformation generated via operations of the mouse/keyboard 13 or thedisplay controller 19 is inputted to the CPU 10, and the CPU 10generates display information and sound information for the display 14and the speaker 15 to output.

The vital sign circle radar device 100 is connected to device 22 formeasuring blood oxygen saturation level (or biological signal detectiondevice) via communication interface 16. The blood oxygen saturationlevel measuring device 22 is a device for measuring SpO₂ value ofpatient. In the embodiments, as an example of the communicationinterface 16, RS-232C etc. is utilized.

In the embodiments, examples of operating systems (OS) for the vitalsign circle radar device 100 are Microsoft's Windows™ XP, NT, 2000,98SE, ME, or CE. In alternative embodiments, the functions of the vitalsign circle radar device 100 are accomplished with hardware logic (notshown) without the use of a CPU. The hardware configuration or CPUconfiguration can be modified by well-known techniques by those skilledin the art.

The “ECG” described in the embodiments is obtained by measuringelectrical potential difference on the heart between two points on thepatient's body. Therefore, the terms “ECG measurement” etc. used hereininclude the operations of measuring the heart's electrical potentialetc.

3. Embodiments

The “vital sign display device” includes any device that displays vitalsign. For example, the “vital sign display device” corresponds to vitalsign circle radar device 100 illustrated in FIG. 3 as an embodiment. The“biological signal obtaining means” includes any means that has afunction for obtaining biological signal. In the embodiments, thebiological signal obtaining means corresponds to CPU 10 of the vitalsign circle radar device 100 that executes a process of step S609 inFIG. 6. The “biological signal” includes any biological signal. In theembodiments, the “biological signal” corresponds to an identified valuedata or SpO₂ value at step S609 in FIG. 6.

The “determining means” includes any means that has a function fordetermining whether living body condition represented by the biologicalsignal is abnormal or not based on the obtained biological signal. Inthe embodiments, the determining means corresponds to CPU 10 thatexecutes processes of step S611 and S613 in FIG. 6.

The “vital sign displaying means” includes any means that has a functionfor displaying the vital sign. In the embodiments, the vital signdisplaying means corresponds to CPU 10 that executes processes of stepS615 and S617, or step S619 and S621 in FIG. 6. The “display styleselecting means” includes any means that has a function for selectingdisplay style. In the embodiments, the display style selecting meanscorresponds to CPU 10 that executes processes of setting display timefor one lap of circle radar 50 at step S605 in FIG. 6. The “vital signitem name displaying means” includes any means that has a function fordisplaying item name of the vital sign. In the embodiments, the vitalsign item name displaying means corresponds to CPU 10 that executesprocess of step S607 in FIG. 6.

4. Example of Vital Sign Circle Radar to be Displayed

An example of the vital sign circle radar to be displayed will bedescribed. The vital sign circle radar creation process will bedescribed in the next section.

FIG. 4 shows an example of the screen displayed by a vital sign circleradar creation process performed by the CPU 10.

As shown in the drawing, a vital sign circle radar 50 for VPC(ventricular premature contraction), a vital sign circle radar 51 forheart rate (HR), vital sign circle radar 52 for QT (QT interval), and avital sign circle radar 53 for SpO₂ value are displayed on the displayscreen 14. In this embodiment, at least one of the vital sign circleradars for VPC, HR, QT and SpO₂ selected in advance by the user isdisplayed.

By each vital sign circle radar, the status of a vital sign is displayedas described in the section “1. Outline of Vital Sign Circle Radar to beDisplayed.” More specifically, an indication point moves in each vitalsign circle radar as the measurement of a biological signal proceeds,and, when the living body is in an abnormal condition (the biologicalsignal is showing an abnormal value), an abnormality indicator 60 (red)is displayed as the vital sign. When the living body is in a normalcondition (the biological signal is showing a normal value), a normalityindicator 62 (green) is displayed as the vital sign.

The electrocardiogram of the lead II as a representative lead, the trendof SpO₂ value obtained from a blood oxygen saturation level measuringdevice 22, and so on are also displayed on the display screen 14. Theelectrocardiogram and the trend of SpO₂ value can be displayed in adifferent style depending on the selection of the user. Anelectrocardiogram of another lead may be displayed or the display may beomitted. In this embodiment, a lead in which the amplitude is large isautomatically selected and displayed as a representative lead.

Although VPC, HR, QT, and SpO₂ are shown as vital sign items to beselected by the user in this embodiment, the present invention is notlimited thereto. The vital sign items to be employed can be changed bymeans known to those skilled in the art. For example, only a vital signcircle radar for VPC may be displayed, or vital sign circle radars forVPC and SpO₂ value may be displayed. Alternatively, a circle radar foran item other than the above four vital sign items (abnormal STelevation, for example) may be displayed.

By the display of the vital sign circle radar as described above, theuser of the vital sign circle radar device 100 can obtain informationabout when and how often abnormalities of a biological signal occurredintuitively and easily.

5. Vital Sign Circle Radar Creation Process

5-1. Precondition for Vital Sign Circle Radar Creation Process

As a precondition for the vital sign circle radar creation process, theCPU 10 of the vital sign circle radar device 100 obtains 12-leadelectrocardiograms via ECG electrodes 20 attached to the patient's bodyand an amplifier 11 and extracts an electrocardiographic waveform andthe identified value (recognized value) data of the electrocardiographicwaveform. The 12-lead electrocardiograms are twelve-patternelectrocardiograms which are obtained from several to dozen electrodesattached to a living body. The identified value data are used todetermine the abnormality of a biological signal in this embodiment. TheSpO₂ value is measured by the blood oxygen saturation level measuringdevice 22.

The flowchart in FIG. 6 shows that the CPU 10 performs the processes ofreceiving the recognized value data and the SpO₂ value and displaying avital sign circle radar based on them.

The CPU 10 continuously records digital data (electrocardiographicwaveform data) obtained via the ECG electrodes 20 in the memory 17 (orthe F-ROM 18) for each of the 12 leads. FIG. 5 is a graph schematicallyshowing the ECG data (vertical axis: electric potential (voltage),horizontal axis: time) recorded for one of the leads. As shown in FIG.5, the CPU 10 extracts identified value data R (R potential or R-waveheight), T (T potential or T-wave height), Q (Q potential or Q-waveheight), ST (ST level), QT (QT interval), and RR (RR interval) based onthe recognition of P-wave, Q-wave, R-wave, S-wave, ST-segment, andT-wave, respectively, in the electrocardiogram and records them in thememory 17 (or the F-ROM 18). The CPU 10 recognizes a heartbeat and eachwave in the electrocardiogram by the following process, for example,when the waveform is normal.

(1) Recognition of a Heartbeat: After sampling electrocardiographicwaveform data (potential or voltage value) for a predetermined period oftime, the CPU 10 recognizes an R-wave, which is a local maximumcomponent exceeding a prescribed threshold, and the next R-wave (a localmaximum component exceeding a prescribed threshold) and recognizes theRR interval as a heartbeat. At this time, T-wave components, which arelocal maximums other than the R-waves (having a frequency lower thanthat of R-waves) may be removed with a low-cut filter.

(2) P-wave: A local maximum which appears 200 to 300 msec(mili-second)before an R-wave is recognized as a P-wave.

(3) Q-wave: A local minimum which appears immediately before an R-waveis recognized as a Q-wave.

(4) S-wave: A local minimum which appears immediately after an R-wave isrecognized as an S-wave.

(5) T-wave: A local maximum which appears between two R-waves isrecognized as a T-wave.

(6) ST-segment: A linear interpolation is performed between an S-waveand a T-wave on the electrocardiogram, and the part which appears as alocal maximum component between them is recognized as an ST-segment.

Noises with abnormal periods are generated and the extraction ofidentified values cannot be made precisely depending on the motion ofthe patient during the measurement of an electrocardiogram. As a methodfor removing such noises and obtaining precise identified value data,the technique disclosed in JP-A-Hei 6-261871, for example, may be used.

5-2. Vital Sign Circle Radar Creation Process

In this embodiment, an example in which the CPU 10 of the vital signcircle radar device 100 creates a vital sign circle radar based on anelectrocardiogram and the SpO₂ value of a patient will be described. Thevital sign circle radar creation process is performed per heartbeat. Theelectrocardiographic data sampling frequency is selected from, forexample, 125, 250, 500 or 1000 Hz.

The vital sign circle radar creation process may be performed per a unitother than heartbeat or per predetermined unit time. The unit of thevital sign circle radar creation process and the electrocardiographicdata sampling frequency may be changed by means known to those skilledin the art.

The vital sign circle radar creation process program in this embodimentwill be described with reference to the flowchart in FIG. 6.

The CPU 10 of the vital sign circle radar device 100 performs a processof inputting a vital sign item selected by the user (step S601). The CPU10 performs a process of inputting a scheduled measurement period (whichcorresponds to the “measurement period”) selected by the user (stepS603). The CPU 10 may output an interactive interface on the displayscreen 14 to receive the input of the vital sign item and the scheduledmeasurement period from the user. Alternatively, these items may beincorporated in the specifications of the vital sign circle radar devicein advance. Here, the vital sign items “VPC, HR, QT and SpO₂ value” anda scheduled measurement period of “20 minutes” are previously set in theF-ROM 18 of the vital sign circle radar device 100.

The CPU 10 displays a circle radar on the display screen 14 based on thevital sign item inputted in step S601 and the scheduled measurementperiod inputted in step S603 (step S605). More specifically, a circleradar having an entire circle display period (which corresponds to the“entire display period”) which is equal to the scheduled measurementperiod. Although the “entire circle display period” is equal to thescheduled measurement period in this embodiment, the present inventionis not limited thereto. A period of time obtained by adding apredetermined period of time to the scheduled measurement period may beautomatically set as the entire circle display period.

Then, the CPU 10 displays the vital sign name at the center of thecircle radar (step S607). More specifically, when the vital sign item isSpO₂ value and the entire circle display period is 20 minutes, the CPU10 displays a circle radar on the display screen 14 and “SpO₂” at thecenter of the circle radar (see a circle radar 53 in FIG. 4).

The CPU 10 performs a process of obtaining identified value data and theSpO₂ value (step S609 in FIG. 6). More specifically, the CPU 10 recordsthe identified value data and the SpO₂ value in the memory 17 (or theF-ROM 18) via the ECG electrodes 20 and the blood oxygen saturationlevel measuring device 22. The CPU 10 determines whether identifiedvalue data corresponding to a heartbeat have been obtained (step S610).If not, the CPU 10 performs the process in step S609 again. Theprocesses in and after step S611 in FIG. 6 are the same as the procedureof the vital sign circle radar creation program corresponding to oneheartbeat. Thus, during the measurement of the biological information,the procedure of the vital sign circle radar creation program shown inand after step S611 in FIG. 6 is repeated at every heartbeat.

The CPU 10 performs an abnormality determination process based on thedata (step S611). In this embodiment, an abnormality determinationprocess is performed on the vital sign item selected from VPC, HR, QT,and SpO₂ value and inputted in step S601.

More specifically, the CPU 10 performs a subroutine of the abnormalitydetermination process for the vital sign item selected in advance by theuser in step S611. As the abnormality determination process, the CPU 10performs a process shown in the flowchart in FIG. 7 when VPC has beenselected, a process shown in the flowchart in FIG. 8 when HR has beenselected, a process shown in the flowchart in FIG. 9 when QT has beenselected, or a process shown in the flowchart in FIG. 10 when SpO₂ valuehas been selected. The abnormality determination processes will bedescribed later.

The CPU 10 performs a process of displaying on the display screen 14according to the result of the vital sign abnormality determinationprocess.

The CPU 10 determines whether it is determined that the vital sign isabnormal by the vital sign abnormality determination process (stepS613). When the vital sign is normal, the CPU 10 calculates anindication area in the vital sign circle radar for the vital sign (stepS619) and displays green in the indication area (step S621) (see anormality indicator 62 in FIG. 4).

The calculation of the indication area is performed based on themeasurement start time, the measurement time and the entire circledisplay period. More specifically, when “the measurement start time is0:00, the measurement time is 0:10 and the entire circle display periodis 20 minutes”, for example, the indication area is about 180 degreeaway from the display start point of the circle radar.

If it is determined that the vital sign is abnormal in step S613, theCPU 10 calculates an indication area in the vital sign circle radar forthe vital sign (step S615) and displays red in the indication area (stepS617) (see an abnormality indicator 60 in FIG. 4). The calculation ofthe indication area is the same as above.

After the process in step S621 or S617, the CPU 10 determines whetherthe vital sign measurement process has been completed (step S623). Ifnot, the processes in and after step S609 are repeated. If it isdetermined that the vital sign measurement process has been completed,the CPU 10 finishes the operation.

When there are a plurality of vital signs on which the CPU 10 has toperform an abnormality determination process, the processes in and afterstep S613 and before step S623 are performed on each vital sign and thenthe process in step S623 is performed.

5-3 Vital Sign Abnormality Determination Process

The abnormality determination process which the CPU 10 performs in stepS611 in FIG. 6 will be described.

As the abnormality determination process, the CPU 10 performs a process(vital sign abnormality determination process means) shown in theflowchart in FIG. 7 when VPC has been selected, a process shown in theflowchart in FIG. 8 when HR has been selected, a process shown in theflowchart in FIG. 9 when QT has been selected, or a process shown in theflowchart in FIG. 10 when SpO₂ value has been selected. In theabnormality determination processes described below, the CPU 10 usesidentified value data and other data necessary for the abnormalitydetermination (which will be described in the description of eachabnormality determination process) recorded in the memory 17 (or theF-ROM 18).

(1) Abnormality Determination Process for VPC

FIG. 7 is a flowchart of the abnormality determination process for VPC.

In this embodiment, VPC (ventricular premature contraction) isdetermined as “abnormal” when the patient is having ventricularpremature contractions and as “normal” when the patient having noventricular premature contraction.

The CPU 10 of the vital sign circle radar device 100 determines whetherthere is a P-wave based on the identified value data recorded in thememory 17 (or the F-ROM 18) (step S701 in FIG. 7). More specifically,the CPU 10 determines whether there is a local maximum (P-wave) 200 to300 msec before each R-wave in all the 12 leads. If there is a P-wave inat least one lead, the CPU 10 determines that “there is a P-wave.”

If it is determined that there is a P-wave, the CPU 10 interprets thedetermination result as “normal” (step S707). If it is determined thatthere is no P-wave, the CPU 10 determines whether the primary directionsof QRS-waves are the same as the direction of T-waves (step S703). Morespecifically, the CPU 10 determines that “the primary directions ofQRS-waves are the same as the direction of T-waves” when the sign (plusor minus) of the R-potential (or R-wave height) value (mV, for example)is the same as that of the T-potential (or T-wave height) in at leastsix of the 12 leads.

If it is determined that the primary directions of QRS-waves are thesame as the direction of T-waves, the CPU 10 performs the process instep S707. If it is determined that the primary directions of QRS-wavesare not the same as the direction of T-waves, the CPU 10 determineswhether the RR interval is greater than 80% of the average of RRintervals in a normal waveforms (step S705). More specifically, the CPU10 determines that “the RR interval is greater than 80% of the averageRR interval in a normal waveform” when the average of the RR-intervals(unit: msec, for example) in all the 12 leads in one heartbeat underexamination is greater than 80% of the average of RR intervals (exceptthose in abnormal waveforms) in all the 12 leads in the past fiveminutes.

If it is determined that the RR interval is greater than 80% of theaverage of RR intervals in normal waveforms, the CPU 10 performs theprocess in step S707. If it is determined that the RR interval is notgreater than 80% of the average of RR intervals in normal waveforms, theCPU 10 interprets the determination result as “abnormal” (step S709).

Then, the CPU 10 performs the processes in and after step S613 in FIG. 6based on the determination result obtained in the process in step S707or step S709.

(2) Abnormality Determination Process for HR

FIG. 8 is a flowchart of the abnormality determination process for HR(heart rate). The HR is determined as “abnormal” when the heart rate ishigher than a predetermined value or lower than a predetermined valueand otherwise determined as “normal.” The CPU 10 calculates the averageof RR intervals (unit: sec, for example) in all the 12 leads in oneheartbeat under examination and obtains heart rate data by dividing 60by the average of the RR intervals.

The CPU 10 determines whether the heart rate is 50 (per minute) or lower(bradycardia) (step S801 in FIG. 8). If it is determined that the heartrate is 50 or lower, the CPU 10 interprets the determination result as“abnormal” (step S805). If it is determined that the heart rate is not50 or lower, the CPU 10 determines whether the heart rate is 100 orhigher (tachycardia) (step S803).

If it is determined that the heart rate is 100 or higher, the CPU 10performs the process in step S805. If it is determined that the heartrate is not 100 or higher, the CPU 10 interprets the determinationresult as “normal” (step S807).

Then, the CPU 10 performs the processes in and after step S613 in FIG. 6based on the determination result obtained in the process in step S805or step S807.

(3) Abnormality Determination Process for QT

FIG. 9 is a flowchart of the abnormality determination process for QT(QT interval). In this embodiment, QT is determined as “abnormal” when aQTc value obtained by correcting a QT interval value is higher than apredetermined value or a lower than a predetermined value and otherwiseas “normal.” For example, the CPU 10 obtains the data of the average ofQTc values in all the 12 leads in one heartbeat under examination as QTinterval value (unit: msec, for example). A QT interval value is, forexample, the interval between a Qb point obtained based on a Q-wave anda Te point obtained based on a T-wave on an electrocardiogram. The CPU10 calculates a QTc value by dividing a QT interval value by 4RR (squareroot of the RR interval), for example.

The CPU 10 determines whether the QTc interval is 0.46 seconds or longer(step S901 in FIG. 9). If it is determined that the QTc interval is 0.46seconds or longer (prolonged QT interval), the CPU 10 interprets thedetermination result as “abnormal” (step S905). If it is determined thatthe QTc interval is not longer than 0.46 seconds, the CPU 10 determineswhether the QTc interval is 0.34 seconds or shorter (step S903).

If it is determined that the QTc interval is 0.34 seconds or shorter(shortened QT interval), the CPU 10 performs the process in step S905.If it is determined that the QTc interval is not 0.34 seconds orshorter, the CPU 10 interprets the determination result as “normal”(step S907).

Then, the CPU 10 performs the processes in and after step S613 in FIG. 6based on the determination result obtained in the process in step S905or S907.

(4) Abnormality Determination Process for the SpO₂ Value

FIG. 10 is a flowchart of the abnormality determination process for theSpO₂ value. In this embodiment, the SpO₂ value is determined as“abnormal” when it is lower than a predetermined value and otherwise as“normal.” The CPU 10 performs the following determination using the SpO₂value recorded in the memory 17 (or F-ROM 18).

The CPU 10 determines whether the SpO₂ value is 90% or lower (step S101in FIG. 10). If it is determined that the SpO₂ value is 90% or lower,the CPU 10 interprets the determination result as “abnormal” (stepS103). If it is determined that the SpO₂ value is not 90% or lower, theCPU 10 interprets the determination result as “normal” (step S105).

Then, the CPU 10 performs the processes in and after step S613 in FIG. 6based on the determination result obtained in the process in step S103or step S105.

5-3 Modification of Vital Sign Circle Radar Creation Process etc

The abnormality determination process for each of the vital signs shownas examples in this embodiment has been described. In the aboveembodiment, the abnormality determination process in step S613 in FIG. 6is performed on all the vital sign items inputted in step S601 and thedisplay process in and after step S613 is performed on every vital signitem. Then, when the display process is completed for every vital signitem, the vital sign circle radar creation process corresponding to oneheartbeat is completed.

The algorithm of the vital sign circle radar creation process is notlimited to the one described in the above embodiment and anotheralgorithm may be employed. For example, an algorithm is used in which anabnormality determination process and a display process are sequentiallyperformed on each vital sign item instead of an algorithm in which adisplay process is performed on every vital sign item after an abnormaldetermination process has been performed on every vital sign item.

Also, the algorithm of vital sign circle radar creation process, thealgorithm of each of the abnormality determination processes, the colorsto be displayed on the display screen 14 and so on described in theabove embodiment are illustrative and may be changed by means known tothose skilled in the art.

For example, the display process in steps S615, S617, S619 and S621 maybe changed as follows.

This variation relates to saving time and energy in the display process.More specifically, the CPU 10 performs the processes in and after stepS619, not every time the CPU 10 determines that the vital sign is normalin step S613 but when the determination that the vital sign is normalcontinues for five seconds or longer, for example. On the other hand,the CPU 10 performs the display process in and after step S615 everytime it is determined that the vital sign is abnormal in step S613.According to the variation of the display process, it is possible tosave time and energy in the display process when the vital sign isnormal. The reference time (five seconds or longer) in the case wherethe vital sign is normal as described above is illustrative and may bechanged depending on the length of the entire circle display period ofthe circle radar.

6. Effects of Embodiment

According to the above embodiment, the user of the vital sign circleradar device 100 can check and determine the status of the vital sign ofthe patient with ease.

In conventional vital sign display methods, a trend graph showing thechanges in the value (parameter) of a biological signal within apredetermined period of time (the last one minute, for example) isdisplayed or the latest value of a biological signal is displayed atsuccessive intervals. In such a case, it is difficult to check thehistory of abnormalities of the biological signal.

In this regard, according to the vital sign display method of the aboveembodiment, it is possible to check the history of the vital sign easilywith a circle radar 50 (see FIG. 4) which can cover the length of timeit takes to carry a patient on an ambulance (15 to 20 minutes ingeneral). Thus, the user of the vital sign circle radar device 100 canvisually recognize the information about when and how often theabnormalities of the biological signal occurred.

In the embodiment, the vital sign is displayed by the circle radar 50and the like. Thus, the user can get the overall perspective of eachvital sign without largely moving the line of sight, and can easilycheck the status of the vital sign within the measurement period.

Moreover, in this embodiment, since the vital sign is displayed by avital sign circle radar by which it can be determined whether the vitalsign is normal or abnormal, more information useful to diagnose thecondition of the patient can be arranged in the display screen than whenthe original data of the vital sign is displayed (for example, when thechanges in heart rate is shown in a graph). Also, a plurality of vitalsigns can be displayed simultaneously with ease.

As described above, the embodiment is characterized in that the value(parameter) of a biological signal is displayed in such a vital signdisplay style (radar) that it can be determined whether the vital signis normal or abnormal. Thus, the user can grasp an abnormality of theliving body (presence or absence of an abnormal value of a biologicalsignal) promptly.

Also in the embodiment, since the vital sign is displayed in the form ofa circle (circle, ring, or doughnut shape), the effect of giving a senseof security to the patient who sees the display screen can be expected.

7. Other Functions of the Vital Sign Circle Radar Device

In addition to the above-mentioned vital sign circle radar generatingprocess, examples of optional functions of the vital sign circle radardevice 100 will be described below.

7-1. Display of Heartbeat Condition

The vital sign circle radar device 100 displays a specific flashingsymbol (or mark) in order to show a heartbeat condition (whichcorresponds to the term “means for outputting heartbeat-relatedinformation by varying display style”). More specifically, the CPU 10processes a display of the flashing heart mark according to the heartrhythm measured, as illustrated in FIG. 4.

The user can confirm that the vital sign circle radar device 100 isrunning normally, and can also check the patient's heartbeat condition.In an alternative embodiment, the device outputs a specific sound (e.g.bleep sound) from the speaker 15 according to the heart rhythm, inconjunction with the flashing mark or instead of the flashing mark.

7-2. Warning for Impracticable Analysis

The vital sign circle radar device 100 displays a certain warning duringthe vital sign circle radar generating process when an ECG electrode 12is detached from the patient or when trouble occurs in the generatingprocess (which corresponds to the term “means for outputting warningsignal when the vital sign analysis can not be executed”). Morespecifically, the CPU 10 displays a warning message stating “electrodedetached” etc., on displaying area of “diagnostic information” ondisplay 14.

The user who sees the warning can promptly understand that the vitalsign circle radar generating process has been interrupted by thetrouble. In alternative embodiments, in order to draw the user'sattention to the display, the CPU 10 changes the color of the wholedisplay or the color of part of the display, or outputs a warning sound(e.g. an alarm sound).

8. Other Embodiments 8-1 Modification of Vital Sign Display Style

Although FIG. 4 is shown as an example of the screen displayed by thevital sign circle radar device 100 in the above embodiment, the presentinvention is not limited thereto. As other embodiments of vital signdisplay style, the display styles shown in FIG. 11 may be employed. Theoutline of each display style will be described.

FIG. 11A shows an example in which the vital signs are displayed withbar radars. In the drawing, a radar 70 for VPC and the like aredisplayed on the display screen 14. More specifically, indication pointsmove from left to right on the screen as the measurement of the vitalsigns of the patient proceeds. The normal and abnormal conditions areindicated in the same manner as in the above embodiment. The entiredisplay period of the bar radars is determined according to themeasurement period selected by the user.

FIG. 11B shows an example in which a vital sign is displayed with aloop-shaped radar (ring-shaped radar or doughnut-shaped radar). In thedrawing, a radar 80 for the SpO₂ value is displayed on the displayscreen 14. Unlike in the above embodiment, the current vital sign isdisplayed in a fixed position and the point indicating the measurementstart time moves in this display style. More specifically, an indicationpoint 83 indicating the measurement start time moves clockwise as themeasurement proceeds while an indication point 82 indicating the currentmeasurement time (the latest measurement time) is located at the uppercenter of the radar 80. Abnormality indication marks 84 as marksindicating abnormal conditions are displayed around the radar 80 so thatthe normal and abnormal conditions can be discriminated from each other.

FIG. 11C shows an example in which a vital sign is displayed with aline. In the drawing, a line 90 for VPC is displayed on the displayscreen 14. More specifically, an indication point 91 moves clockwisefrom the upper center of the screen as the measurement of the vital signof the patient proceeds. When the vital sign is abnormal, an abnormalityindicator 92 or an abnormality indicator 93 indicating an abnormalcondition is displayed on the line 90.

In the embodiments, as an example of the “vital sign displaying means”,the process of displaying a vital sign on display 14 is illustrated. Inalternative embodiments of the “vital sign display means (or “vital signoutput means”), the vital sign can be outputted in computer-readablestorage media such as memory card or CD-ROM. The vital sign can beoutputted to connection means (e.g. telephone lines, wirelesscommunication, the Internet, wire communication, infrared datacommunication, mobile phone, Bluetooth, PHS, or the like). The vitalsign can be outputted as printed hard copy, facsimile, or the like.

The term of “vital sign displayed object” in the claims includes anyoutput where a vital sign is visually recognizable. For example, adisplayed object, a hard copy output, or a facsimile output of vitalsign is included in the “vital sign displayed object”.

8-2. Modification of Style of Displaying Abnormal Condition

Although the case where an indication point corresponding to an abnormalcondition is displayed in red (see abnormality indicator 60 in FIG. 4)is described as an example of the style of displaying a vital sign whenthe living body is in an abnormal condition (the biological signal showsan abnormal value) in the above embodiment, the present invention is notlimited thereto. The following displaying method may be employed asanother embodiment of the style of displaying an abnormal condition.

A first variation of the style of displaying an abnormal condition is toblink the indication point indicating an abnormal condition. Morespecifically, the abnormality indicator 60 shown in FIG. 4 is blinked inred and the like.

A second variation of the style of displaying an abnormal condition isto change the display style depending on to the level of the abnormalvalue. More specifically, the degree of abnormality (including theseverity or seriousness) is classified in levels (ranked) and the color(saturation, lightness or hue, for example) of the indication point ischanged depending on the level. The following chart is an example ofclassification of levels of abnormality of heart rate (HR).

HR<30→Abnormal level=−2 (bradycardia)

30≦HR<50→Abnormal level=−1 (bradycardia)

50≦HR<120→Abnormal level=0 (normal)

120<HR≦180→Abnormal level=1 (tachycardia)

180<HR→Abnormal level=2 (tachycardia)

When the color saturation of the “red” of the abnormality indicator 60(see FIG. 4) is increased, for example based on the levels ofabnormality when the abnormality level is high (a function of a “vitalsign abnormality level indicator means”), it is possible to providedetailed information about the abnormality to the user.

The method of changing the style of displaying depending on the level ofabnormality is not limited to the above example. For example, the sizeof the indicating points may be changed. For example, as shown in FIG.11C, the abnormality indicator 93 is displayed when the abnormalitylevel is low, and the abnormality indicator 92, which is larger in size,is displayed when the abnormality level is high.

8-3. Embodiments of Device Configuration

In the embodiments, the vital sign circle radar device 100 executes bothECG measurement and vital sign circle radar display. In alternativeembodiments, those functions can be separately executed by two or morediscrete devices. For example, one device can execute an ECG measurementand ECG data output, and the other device (which corresponds to “vitalsign display device”) can execute a vital sign circle radar displaybased on the ECG data input.

The configuration of the devices (the number and combination of devices)for performing the process of measuring an electrocardiogram, theprocess of measuring the SpO₂ value, the abnormality determinationprocess and the vital sign display process, respectively, and theconfiguration of the CPU may be changed by means known to those skilledin the art.

For example, although the CPU 10 of the vital sign circle radar device100 performs the abnormality determination for the SpO₂ value accordingto the flowchart shown in FIG. 10 in the above embodiment, the presentinvention is not limited thereto. The CPU in the blood oxygen saturationlevel measuring device 22 may perform the abnormality determination andtransmit the result of the determination (which corresponds to a “signalgenerated based on a biological signal,” which includes a normalitysignal and an abnormality signal, or a normality signal or anabnormality signal, for example) to the CPU 10.

Although the vital sign is displayed based on electrocardiographic dataand the SpO₂ value in the above embodiment, the present invention is notlimited thereto. Auxiliary devices other that the blood oxygensaturation level measuring device 22 may be connected to the vital signcircle radar device 100 as another embodiment. More specifically, ablood pressure measuring device may be connected to the vital signcircle radar device 100 as an auxiliary device and “blood pressure” (BP)may be displayed as the vital sign.

8-4. Application Embodiments of Vital Sign Circle Radar Device

In the embodiments, the vital sign circle radar device 100 is used inambulances. In alternative embodiments, the device can be used in anyemergency medical arena in a portable form, used for home medical careby setting the device in a home, or used for living bodies includinghuman or animals.

Devices that have similar functions with that of the vital sign circleradar device 100 can be installed in the driver's seat of an automobileor an electric train, an airplane cockpit, or the like, in order toprevent a serious accident from occurring when the driver develops aheart attack due to myocardial infarction etc. In other embodiments,such devices can be installed on a toilet seat, etc., for daily healthcare. For those applications, it is advantageous for the ECG electrodes20 to be installed in an area with which the subject's body necessarilymakes contact, such as a handle, toilet seat, handrail, or the like.

8-5. Program Execution

In the embodiments, the computer program for the CPU 10 is stored in theF-ROM 18. The computer program can be installed on the hard disk etc.from an installation CD-ROM (not shown). In alternative embodiments, theprogram can be installed from computer-readable storage media suchDVD-ROM, a flexible disk (FD) or IC card (not shown). Alternatively, theprogram can be downloaded to the devices via the communications lines.The program storied on CD-ROM may also be directly executed although theprogram stored on CD-ROM can be executed indirectly by installing theprogram.

Computer-executable programs used in the embodiments include a programto be executable just after installation, a program that needs to beconverted to another format (e.g. decompressing compressed data), or aprogram to be executable within a module.

A general description of the present invention as well as preferredembodiments of the invention has been set forth above. It is to beexpressly understood, however, the terms described above are for purposeof illustration only and are not intended as definitions of the limitsof the invention. Those skilled in the art to which the presentinvention pertains will recognize and be able to practice othervariations in the system, device, and methods described which fallwithin the teachings of this invention. Accordingly, all suchmodifications are deemed to be within the scope of the invention.

1. A vital sign display device for displaying a vital sign, comprising:means for obtaining a biological signal; means for determining whetherliving body condition represented by the biological signal is abnormalor not, which is based on the obtained biological signal; and means fordisplaying a vital sign obtained from the biological signal, that allowsto discriminate whether the condition is abnormal or not, which is basedon the determination results from the determining means, wherein thevital sign is arranged in time series that allows to provide history ofthe vital sign.
 2. A computer readable medium having stored thereon thecomputer program for a vital sign display device that displays a vitalsign, wherein the program is implemented in a computer and capable ofcausing the computer to perform: means for obtaining a biologicalsignal; means for determining whether living body condition representedby the biological signal is abnormal or not, which is based on theobtained biological signal; and means for displaying a vital signobtained from the biological signal, that allows to discriminate whetherthe condition is abnormal or not, which is based on the determinationresults from the determining means, wherein the vital sign is arrangedin time series that allows to provide history of the vital sign.
 3. Avital sign display device for displaying a vital sign, comprising: meansfor displaying a vital sign, obtained from the biological signal orsignal generated from the biological signal, that allows to discriminatewhether living body condition represented by the signal is abnormal ornot, wherein the vital sign is arranged in time series that allows toprovide history of the vital sign.
 4. The device according to claim 1,wherein the vital sign is displayed so as to follow a circular shapeaccording to time series of the vital sign.
 5. A vital sign displaydevice for displaying a vital sign, comprising: means for obtaining abiological signal; means for determining whether living body conditionrepresented by the biological signal is abnormal or not, which is basedon the obtained biological signal; and means for displaying a vital signobtained from the biological signal, that allows to discriminate whetherthe condition is abnormal or not, which is based on the determinationresults from the determining means, wherein the display is executed bymoving a display object in the direction to draw a circular shapeaccording to time series of the vital sign.
 6. The device according toclaim 1, further comprising means for selecting display styles, whereinthe display style selecting means determines entire display periodcorresponds to display area for the vital sign by correlating withmeasurement period of the vital sign.
 7. The device according to claim1, further comprising means for displaying item name of vital sign,wherein the vital sign item name displaying means displays the item nameby relating the item name to the displayed vital sign.
 8. The deviceaccording to claim 1, wherein the display style of vital sign is changedto another style when the abnormal condition occurs.
 9. The deviceaccording to claim 1, wherein the vital sign comprises at least an itemof VPC (ventricular premature contraction), HR (heart rate), QTinterval, or SpO₂ value (oxygen saturation in blood).
 10. A vital signdisplay device for displaying a vital sign, a central processing unit(CPU) of the vital sign display device is to execute the procedures of:obtaining a biological signal; determining whether living body conditionrepresented by the biological signal is abnormal or not, which is basedon the obtained biological signal; and instructing to display a vitalsign obtained from the biological signal, that allows to discriminatewhether the condition is abnormal or not, which is based on thedetermination results, wherein the vital sign is arranged in time seriesthat allows to provide history of the vital sign.
 11. A vital signdisplay device for displaying a vital sign, a central processing unit(CPU) of the vital sign display device is to execute the procedures of:instructing to display a vital sign, obtained from a biological signalor a signal generated from the biological signal, that allows todiscriminate whether living body condition represented by the signal isabnormal or not, wherein the vital sign is arranged in time series thatallows to provide history of the vital sign.
 12. A vital sign displaydevice for displaying a vital sign, a central processing unit (CPU) ofthe vital sign display device is to execute the procedures of: obtaininga biological signal; determining whether living body conditionrepresented by the biological signal is abnormal or not, which is basedon the obtained biological signal; and instructing to display a vitalsign obtained from the biological signal, that allows to discriminatewhether the condition is abnormal or not, which is based on thedetermination results, wherein the display is executed by moving adisplay object in the direction of following a circular shape accordingto time series of the vital sign.
 13. A vital sign displayed objectrepresenting a vital sign, wherein the vital sign displayed objectrepresents a vital sign obtained from a biological signal, that allowsto discriminate whether living body condition represented by thebiological signal is abnormal or not, wherein the vital sign is arrangedin time series that allows to provide history of the vital sign.
 14. Amethod for displaying a vital sign comprising the steps of: obtaining abiological signal; determining whether living body condition representedby the biological signal is abnormal or not, which is based on theobtained biological signal; and displaying a vital sign obtained fromthe biological signal, that allows to discriminate whether the conditionis abnormal or not, which is based on the determination results, whereinthe vital sign is arranged in time series that allows to provide historyof the vital sign.
 15. A method for displaying a vital sign comprisingthe steps of: obtaining a biological signal; determining whether livingbody condition represented by the biological signal is abnormal or not,which is based on the obtained biological signal; and displaying a vitalsign obtained from the biological signal, that allows to discriminatewhether the condition is abnormal or not, which is based on thedetermination results from the determining means, wherein the display isexecuted by moving a display object in the direction of following acircular shape according to time series of the vital sign.